Machine for producing dispersions of liquids in air or other gases for the production of fogs



w. L. TENNEY ET AL 2, MACHINE FOR PRODUCING DISPERSIONS OF LIQUIDS INAIR OR OTHER GASES FOR THE PRODUCTION OF FOGS I 3 Sheets-Sheet 1 March13, 1956 Filed Dec. 26, 1950 UK &3 0 m .N K m m MIL EC/./.A M m m L c Amv MS W V. B 3 J wk on mm W 7 Ck m 2 k 9 6 March 13, 1956 w, ENNE ETAL2,738,334

MACHINE FOR PRODUCING DISPERSIONS OF LIQUIDS IN AIR OR OTHER GASES FORTHE PRODUCTION OF FOGS Filed D60. 26, 1950 5 Sheets-Sheet 2 SOQV/LLE EKvox A Tron/V0 3 M r 1956 w. TENNEY ETAL 2,738,334

MACHINE FOR PRODUCING DISPERSIONS OF LIQUIDS IN AIR OR OTHER GASES FORTHE PRODUCTION OF FOGS Filed Dec. 26, 1950 3 Sheets-Sheet 3 0 0 J Q l" kg r O R v 0 1W ATTORNEYS UnitedStates PatentO MACHINE FOR PRODUCINGDISPERSIONS F LIQUIDS IN AIR OR OTHER GASES FOR THE PRODUCTION OF FOGSWilliam L. Tenney, Dayton, Scoville E. Knox, Phoneton, and Paul A.Frank, Dayton, Ohio, assignors, by mesne assignments, to William L.Tenney, Dayton, Ohio Application December 26, 1950, Serial No. 202,668

9 Claims. I (Cl. 252-359) This invention-relates to fog generators andmore particularly to fog generators of the pulse jet engine type.

,A pulse jet engine has certain advantages from the standpoint ofsimplicity of construction and operation, small number of moving parts,and economy in size, weight and expense. Where such an engine isincorporated in a device for atomizing and distributing a formulation inthe form of a fog and including special materials such as an insecticideor the like for special purposes, it is important to retain theseadvantages which are associated with the engine itself. A fog generatorincorporating a pulse jet engine which functions as a resonantintermittent combustion device rather than as a jet propulsion device,is thus utilized which is simple in construction and mode of operation,which contains a minimum number of moving parts, which is economical inboth its use of fuel for operation of the engine and in effectiveutilization of the formulation to accomplish the desired fogproduction.

It is an object of the present invention to provide such an engine whichis essentially safe and in which the formulation, even thoughcombustible itself, does not create a fire or flame hazard, regardlessof whether or not it may continue to be supplied following the stoppageof the engine.

It is also an object of the invention to provide an improved arrangementfor developing an expelling pressure within the reservoir which containsthe fog-forming formulation which is simple, inexpensive and economicalin construction and operation, having a pressurizing valve and which maybe located in convenient position with a flexible connection extendingto the reservoir.

Referring to the drawing which illustrates a preferred embodiment of theinvention: I

Fig. l is a somewhat schematic layout of a fog generating apparatusconstructed in accordance with the present invention;

charge outlet, indicated at 21.

v 2,738,334 Ice Patented Mar. 13, 1956 in Fig. 1 and has a low point 20upstream from its dis- Such an engine embodiesthe combination of acombustion chamber, valved inlet ports, and a discharge tube forming asystem res- Onantin gases which operates, after being started, withself-induced charging, ignition and scavenging, thus constituting aresonant intermittent combustion device.

The system also embodies a starting battery 25 controlled by a switch 26which closes the circuit to the spark coil 27, providing the hightension ignition spark for spark plug 15. An indicating device 28 may beused to show when the ignition circuit is closed and outside terminal 29may be provided for Connection to an external battery source whendesired. As will be understood, the hand pump and the spark coil arerequired only for initial starting purposes, the engine thereaftercontinuing to function without the use of either the auxiliary airsupply or the spark coil as more fully as:

scribed in said copending application.

Fuel for operating the engine is contained in fuel tank 30 and suppliedthrough pipe line 31 to selector valve 32 which may be manually adjustedto select fuel either from the tank 30 or through line 33 from anotherexternal tank as desired. The fuel passes through line 34 to a filter 35and float chamber 36 directly to the fuel line 11, the latter beingunder control Of manual shutoff" valve 37 The formulation is suitablycontained in a tank or reservoir 40 which is closed and capable ofretaining an expelling gas pressure. Such pressure is developed from theoperation of the engine itself, this being accomplished through theprovision of the pressurizing valve 42 shown in detail in Fig. 2. Aconnection is made from the combustion chamber 14 of the engine in theform of tube 43 which is capable of withstanding the relatively hightemperatures encountered adjacent the engine and which has sufiicientlylarge flow capacity and is sutficiently close to the engine so that itwill elfectively transmit to the pressurizing valve 42 the rapidlyoccurring but discontinuous high pressure peaks in the combustionchamber. These pressure peaks are transmitted through a passage 45 inthe inner valve body 46 and efiect the raising of the yieldable springor valve 47 against its back plate 48, to release such pressure peaksinto the pressure chamber 5% within the valve. As soon as the pressurepeak passes, the valve member 47 will close and prevent back flow, andhence only the pressure peaks of the combustion chamber are madeeffective within the chamber 50. Since Fig. 2 is a view in sectionthrough a pressurizing valve utilized in connection with the invention;

Fig. 3 is a view in perspective of a commercial form of fog generatingmachine in accordance with the present invention;

Fig. 4 is an end view of the machine; and

Figs. 5 and 6 are vertical sectional and horizontal sectional viewsrespectivelythrough the machine.

Referring first to Fig. l, the apparatus embodies a resonant pulse jetengine indicated generally at 10, a suitable engine for this purposebeing disclosed more in detail in copending application of William L.Tenney, Paul A. Frank and Scoville E. Knox, Serial No. 111,308, filedAugust 19, 1949. In general, such an engine embodies a fuel supply line11, an air Connection 12 supplied from hand pump 13 for startingpurposes, a combustion chamber 14 with a spark plug 15 therein forinitiating combustion, and an elongated discharge tube 16 connected withthe end of the combustion chamber by a conical connecting portion 17.The discharge tube is conveniently formed and bent upon itself as shownthe entire pressurizing valve is relatively close to the engine and itsConnecting line 43 of relatively low flow resistance, the pressure whichis developed and maintained within chamber 50 can be made to closelyapproach the maximum pressure intermittently produced in the combustionchamber itself, thereby developing a continuous pressure within chamber50.

A clean-out plug 51 is provided at the bottom of the pressurizing valveand a pressure supply line 52 extends from chamber 50 to the reservoir40, being connected thereto through a fitting 53 which can be tightenedby means of handles 54 and which preferably embodies a pressureindicating gage 55. I

Since the connecting line 52 is more remote from the engine and is notrequired to transmit rapidly fluctuating pressure waves, it need not beas large in diameter as the tube 43, and in addition may be considerablylonger and still provide for effective transmission of the pressure fromchamber 50 to the interior of the reservoir. Further, the tube 52 doesnot need to be of heat resisting material because the temperature of thegas which it handles is materially lower, and satisfactory results havebeen obtained where a rubber tube was used for this purpose,

The pressure thus-transmitted from chamber 50 to reservoir ill causesthe discharge. of the formulation through a screen 53 enclosingpickup'tube 60, the formulation then flowing through line 6 controlledby manual on and off valve 62 having a control knob 6221 to an automaticshutoff valve 63, such as disclosed in said copending application. Suchautomatic valve. has a pressure conmotion 64- extending back to thecombustion chamber 14' and is normally intended to shut off the dew ofthe formulation immediately upon stoppage of: the engine. The rate offlow for normal purposes is controlled by manual setting of thecontrol-knob 66' operating through flexible shaft or the like 67' whichfunctions to regulate the how control valve 63 thereby regulating thesupply of the formulation at the desired rate.

As shown in Fig. l the formulationis introduced into discharge tube tothroughznozzle. 70 under the pressure and at the controlle ratedesired;Normally upon the stoppage of the engine the supply efformulation alsoimmediately stops. However should the automatic valve 63 for any reasonfail to shut off theflow, itis'quite desirable to prevent the deliveryofthe formulation from the discharge tube si ce such tube is usuallyhighly heated, and if the formulation is allowed to pass out theend21thereof, it may catch fire if of a combustible nature and pro duce anundesirable condition.

In accordance with the present invention it will be seen that the nozzle'79 is arranged downstream from the low point of the discharge tube andat a higher elevation. A drain connection 75 is provided whichcommunicates with the low point of the tube 20 and which may be pernently open but with a relatively restricted flow passage. The operationis as follows. During the time that the engine is operating therestricted. passage through outlet has little effect on the operationsince the passage is so restricted that at most only a smallloss ofpressure occurs. However should there be any continuing fiow of theformulation in through nozzle '70 after the stoppage of the engine, thatmaterial will flow down to the low part of the tube, and will be drawnoff through outlet 75 without flowing out of the normal outlet 21. Tube75 thus withdraws the formulation to a point where it is relativelycool, and spaced from the outlet 21 such that upon delivery from the endof tube 75', it merely drops away without danger of spontaneous ignitionor combustion.

The apparatus is conveniently embodied in the structure shown in Figs. 3to 6 in which the entire apparatus is enclosed within a housing formedby end castings 8i) mounted upon tubular runners 81 and secured at theirupper ends by steel rods 82. The engine itself is enclosed within atubular housing 3 which joins at the discharge end onto a flange 85 ofend casting $0, a neck portion 86 extending in the opposite directionand having a connection for receiving tivo curved discharge tubes 87 and88, connected by rings 8'), and each capable of relative rotationalmovement by applying a twisting force to handles t in order to directthedischarge of the fog in the direction desired. The rings 89 are.detachably secured by toggle clamps 91 providing for quick removal forready cleaning of the discharge tube 16 from the end 21 inwardly to theinjection nozzle 7 0.

The end housing 80 adjacent the discharge end of the engine is providedwith a series of air openings 92 which open into an annular space 93surrounding the cylindrical member 84, through which a flow of air takesplace. This chamber is defined outwardly by a cylindrical member 95, thelatter defining an upper space 6 in which the fuel tank 3% is receivedand hence protected against the high temperature of the engine itself.An outer casing 97 is removably received over the fuel tank to enclosethe upper space 96 and may be secured by spring fasteners 93. The handpump 13, the ilow regulating valve control knob 66 and the quick shutoffvalve 62'and knob 62a are preferably mounted in the opposite end casting30.

A perforated cap ltii) is pivotally securedon the end casting adjacentthe inlet end of the engine, providing an- .additional path for theinflowingairrequired'for' combustion and cooling purposes. The cap 10%also encloses the manual selector valve 32, the filter 35 and floatchamber 36 in the fuel supply line to the engine.

The pressurizing valve 42 ispreferably located outside of the housingadjacent the connecting part 86, and its tube. 43icxtends through theannular space 93 and hence in'thc path-of flow of cooling air so thatitis subjected to a cooling effect through its length. The flow regulatingvalve 68 may be located below'the outer casing and the discharge line 75may merely provide. forwithdrawal of'theunused formulation to a placebeneath or at one side of the apparatus.

The invention therefore provides a simple yet highly satisfactory fogproducing generatorincorporating a pulse jet engine, having a highdegree of safety, embodying a minimum of moving parts, and assuring theproper and safe delivery and discharge of-the'formul'ation both duringThe the running and upon the stopping of the engine. term fog as usedherein is intended to apply to any heterogeneous mixture of: a liqnidphase in'a gaseous phase or any finely divided liquid droplets suspendedin a gas.

While the form of apparatus herein-described constitutes preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from'the scope of the invention whichis defined in the appended claims.

What is claimed is:

l. lna foggenerator having a pulse jet engine including. a combustiontamber and a discharge tube and adapted to develops pulsating dischargepressure through said tube, said discharge tube having a curved portionwith a low point intermediate the ends thereof, a reservoir-containing aformulation for discharge in the form of a fog through said dischargetube, means for supplying said formulation to said discharge tube at apoint downstream thereof andatahigher'level than said low. point, and adrain connection to said low point having a restricted passage forventing undischarged quantities of said formulation upon the stoppage.of said engine at a point remote from said discharge tube.

2. In a fog generator having a pulse jet engine including a combustionchamber and a discharge tube and adapted to develop apulsating dischargepressure through said tube, said discharge tube being curved and havinga low point in advance of the discharge end thereof, means forintroducing a fog-forming formulation into said discharge tube at ahigher level than said low point, and a restricted connection from saidlow point providing for discharge of said formulation from said lowpoint and withdrawal thereof from said tube upon stoppage of said enginewith no substantial loss of operating pressure.

3. In a fog generator having a pulse jet engine including. a combustionchamber and a discharge tube and adapted to develop a pulsatingdischargepressure through said tube, said discharge tube being-curved and havinga low point in advance of the discharge end thereof, means forintroducing a fog-forming formulation into said discharge tube at ahigher level than said low point, means controlled in response to thestopping of said engine for normally stopping the flow of saidformulation, and arestricted connection from said low point providingfor discharge of any remaining quantity of said formulationfrom said lowpoint and withdrawal thereof from said tube upon stoppage of said enginewith no substantial loss of operating pressure.

4. In a fog generator having a pulse jet engine including a combustionchamber and discharge tube and adapted to develop a pulsating dischargepressure through said tube, saiddischarge tube being curved having a lowpoint in advance of the discharge end-thereof, means for introducing afog-forming formulation into said discharge. tube downstream from saidlow point and at a level intermediate that of said low point and that ofthe discharge end of the tube providing for flow of any remainingquantity of said formulation upstream toward said low point uponstoppage of said engine, and a restricted connection from said low pointproviding for discharge of said formulation from said low point andWithdrawal thereof from said tube upon stoppage of said engine With nosubstantial loss of operating pressure.

5. In a fog generator having a pulse jet engine including a combustionchamber and a discharge tube and adapted to develop a pulsatingdischarge pressure through said tube, said discharge tube being curvedand having a low point in advance of the discharge end thereof, meansfor introducing a fog-forming formulation into said discharge tubedownstream from said low point and at a level intermediate that of saidlow point and that of the discharge end of the tube providing for flowof any remaining quantity of said formulation upstream toward said lowpoint upon stoppage of said engine, and a continuously open butrelatively restricted connection to the low point of said tube fordischarge of unused formulation therefrom upon the stoppage of saidengine with no substantial loss of operating pressure.

6. In a fog generator having a pulse jetengine including a combustionchamber and a discharge tube and adapted to develop a pulsatingdischarge pressure through the tube, a closed reservoir for storing aformulation for introduction into said tube to produce the fog, aconnection from said reservoir to said discharge tube for delivery ofsaid formulation thereto, a pressurizing valve having a check valvemember adapted to open automatically in response to said pulsatingpressure and to allow passage of only the pressure peaks from saidcombustion chamber, a relativelyshort connection from said combustionchamber to said pressurizing valve having low flow resistance providingfor effective delivery of said pressure peaks from said chamber to saidvalve to form a continuous pressure, and a relatively longer connectionfrom said pressurizing valve to said reservoir to transmit saidcontinuous pressure to the interior of said reservoir to establish anexpelling pressure therein.

7. In a fog generator having a pulse jet engine including a combustionchamber and a discharge tube and adapted to develop a pulsatingdischarge pressure through the tube, a closed reservoir for storing aformulation for introduction into said tube to produce the fog, aconnection from said reservoir to said discharge tube for delivery ofsaid formulation thereto, a pressurizing valve having a check valvemember adapted to open automatically in response to said pulsatingpressure and to allow passage of only the pressure peaks from saidcombustion chamber, a relatively short connection from said combustionchamber to said pressurizing valve having low flow resistance providingfor efiective delivery of said pressure peaks from said chamber to saidvalve,

of a fog-forming formulation in finely atomized form having a pulse jetengine including a combustion chamber and a discharge tube and adaptedto develop a pulsating discharge pressure through said tube, a closedreservoir for receiving the formulation to be discharged, a connectionfrom said reseivoir to said discharge tube providing for How of saidformulation into said discharge tube, and means for developing anexpelling pressure Within said reservoir including a pressurizing valveresponsive to only the pressure peaks of said combustion chamber, saidpressurizing valve having a check valve member, a relatively shortconnection having low flow resistance from said combustion chamber tosaid pressurizing valve to transmit substantially the full maximumpressure peaks of said combustion chamber to said pressurizing valve toform a continuous pressure, and a connection from said pressurizingvalve to said reservoir adapted to have greater flow resistance thansaid short connection for transmission of said continuous pressure tosaid reservoir to develop an expelling pressure therein.

9. In a fog generator adapted to cause the discharge of a fog-formingformulation in finely atomized form having a pulse jet engine includinga combustion chamber and a discharge tube and adapted to develop apulsating discharge pressure through said tube, a closed reservoir forreceiving the formulation to be discharged, a connection from saidreservoir to said discharge tube providing for flow of said formulationinto said discharge tube, and means for developing an expelling pressurewithin said reservoir including a pressurizing valve, said pressurizingvalve having a check valve member and being operable automatically inresponse to said pulsating discharge pressure a relatively shortconnection having low flow resistance from said combustion chamber tosaid pressurizing valve to transmit substantially the full maximumpressure of said combustion chamber in a series of pressure peaks tosaid pressurizing valve, a pressure chamber for receiving said pressurepeaks and forming a source of continuous pressure, and a connection fromsaid pressurizing valve chamber to said reservoir adapted to havegreater flow resistance than said short connection for transmission ofsaid continuous pressure to said reservoir to develop an expellingpressure therein.

References Cited in the file of this patent UNITED STATES PATENTS1,062,029 Pillsbury May 20, 1913 1,637,898 Evans et a1. Aug. 2, 19271,801,565 Norton Apr. 21, 1931 2,070,038 Batt Feb. 9, 1937 2,408,111Truax et al. Sept. 24, 1946 2,476,171 Williams July 12, 1949 2,529,942Holthouse Nov. 14, 1950 OTHER REFERENCES Technical Development DivisionSummary of Activities No. 15, Federal Security Agency, Public HealthService, Nov. 1, 1948, pages 71-73.

Karcher, German Patent Application 138,004, Feb. 25, 1943, pub. June 11,1948, Frames 890789l1, Reel 83,291.

1. IN A FOG GENERATOR HAVING A PULSE JET ENGINE INCLUDING A COMBUSTIONCHAMBER AND A DISCHARGE TUBE AND ADAPTED TO DEVELOP A PULSATINGDISCHARGE PRESSURE THROUGH SAID TUBE, SAID DISCHARGE TUBE HAVING ACURVED PORTION WITH A LOW POINT INTERMEDIATE THE ENDS THEREOF, ARESERVOIR CONTAINING A FORMULATION FOR DISCHARGE IN THE FORM OF A FOGTHROUGH SAID DISCHARGE TUBE, MEANS FOR SUPPLYING SAID FORMULATION TOSAID DISCHARGE TUBE AT A POINT DOWNSTREAM THEREOF AND AT A HIGHER LEVELTHAN SAID LOW POINT, AND A DRAIN CONNECTION TO SAID LOW POINT HAVING ARESTRICTED PASSAGE FOR VENTING UNDISCHARGE QUANTITIES OF SAIDFORMULATION UPON THE STOPPAGE OF SAID ENGINE AT A POINT REMOTE FROM SAIDDISCHARGE TUBE.
 6. IN A FOG GENERATOR HAVING A PULSE JET ENGINEINCLUDING A COMBUSTION CHAMBER AND A DISCHARGE TUBE AND ADAPTED TODEVELOP A PULSATING DISCHARGE PRESSURE THROUGH THE TUBE, A CLOSEDRESERVOIR FOR STORING A FORMULATION FOR INTRODUCTION INTO SAID TUBE TOPRODUCE THE FOG, A CONNECTION FROM SAID RESERVOIR TO SAID DISCHARGE TUBEFOR DELIVERY OF SAID FORMULATION THERETO, A PRESSURIZING VALVE HAVING ACHECK VALVE MEMBER ADAPTED TO OPEN AUTOMATICALLY IN RESPONSE TO SAIDPULSATING PRESSURE AND TO ALLOW PASSAGE OF ONLY THE PRESSURE PEAKS FROMSAID COMBUSTION CHAMBER, A RELATIVELY SHORT CONNECTION FROM SAIDCOMBUSTION CHAMBER TO SAID PRESSURIZING VALVE HAVING LOW FLOW RESISTANCEPROVIDING FOR EFFECTIVE DELIVERY OF SAID PRESSURE PEAKS FROM SAIDCHAMBER TO SAID VALVE TO FORM A CONTINUOUS PRESSURE, AND A RELATIVELYLONGER CONNECTION FROM SAID PRESSURIZING VALVE TO SAID RESERVOIR TOTRANSMIT SAID CONTINUOUS PRESSURE TO THE INTERIOR OF SAID RESERVOIR TOESTABLISH AN EXPELLING PRESSURE THEREIN.